I think the answer would be because if there is an error in the DNA replication, it would affect one generation of cells. if the error would fall in the transcription or translation, there would only be one cell affected.
Answer:
Phospholipids are amphipathic molecules. This means that they have a hydrophilic, polar phosphate head and two hydrophobic fatty acid tails. These components of the phospholipids cause them to orientate themselves, so the phosphate head can interact with water and the fatty acid tails can't, hence forming a bilayer
Explanation:
I guess you forgot to add the picture or so.
Based on the Complementarity of the 4 nucleotides, The thymine must always be placed in front of the Adenine, and the Cytosine must always be placed in front of the Guanine.
Any change in this rule causes the deformation of the DNA, and can sometimes cause fatal diseases like the melanoma (skin cancer) etc...
Hope this Helps! :)